While a variety of body heating devices have been previously proposed, the present invention concerns personal garments that greatly improve the usefulness and efficiency of certain chemical reaction type heating devices, especially air-activated, disposable heating devices, e.g., flexible packets that contain a mixture of iron powder, activated charcoal, salt, water and wood fiber such as products marketed under the trade name HOTHANDS-2.TM. by Heatmax Inc., P.O. Box 1191, Dalton, GA. When these packets are opened and air is allowed to enter the packet, an exothermic chemical reaction takes place between the components, increasing the temperature of the packet to about 130.degree. F. to 140.degree. F. Current methods of using the heat-producing flexible packets are inconvenient, clumsy and inefficient. The packets are ordinarily placed in a glove, mitten, or shoe, or in a pocket, e.g., a jacket pocket to provide warmth to the hands when the hands are placed in the pocket next to the heated packet. Primarily because a jacket is loose on the body, little if any heat is conducted to the chest or abdomen for warming the core of the body. When placed in a mitten, the heat-producing packet can be wrapped in protective fabric such as a cloth handkerchief. This is awkward and inconvenient. In addition, the packet can become unwrapped and cause overheating of the skin. Another means of using such a packet is to place an adhesive or sticky tape on one side of it and attach the packet to the area of a body garment where warmth is desired. However, packets bonded to garments sometimes fall off after only a short use period and attempts to re-stick the packet are usually unsuccessful because the adhesive is often lost or dried up.
It is well known that other types of personal heating units, e.g., a rigid heater known as the JON-E.RTM. handwarmer manufactured by Aladdin Laboratories, Inc., Minneapolis, MN (U.S. Pat. No. 2,579,620) have been developed. This heater uses a petroleum distillate and a special wick within a metal container wrapped in a cloth bag for warming purposes. Again, the manufacturer recommends that this warmer be placed in a pocket such as a jacket pocket to provide warmth for the hands. In this mode of use, much of the heat is dissipated to the air, and only a small fraction of the heat is conducted to the hands so as to effectively warm the person's hands when the hands are placed in the pocket. Only an insignificant amount of heat, if any, is conducted to the chest or abdomen from the jacket pocket and therefore this mode of use fails completely to elevate the body core temperature which is an important objective of the present invention. These distillate burning units require an open flame to initiate heating and are also heavy and smelly during use. Consequently, the air-activated heating packet described above is preferred for use in the present invention because it is lightweight, flexible, and provides odorless heating. However, prior to the development of the present invention, much of the heat produced by this kind of air-activated, flexible packet was wasted due to the lack of an effective means to efficiently conduct heat to specifically designated parts of the body.
In view of these and other deficiencies of the prior art, it is one object of the present invention to provide garments specifically designed to carry and hold one or more heat-producing packets next to the body at specific locations that provide the user with desired warmth while also providing efficient transfer of heat to the core of the body and improved comfort for the user.
It is another object of the present invention to provide a means whereby a used heating packet may be easily and conveniently removed and replaced with a new heating packet.
It is a further object of the invention to provide a garment that will hold a heating packet close to the body while a person is engaged in physical activity such as hunting, skiing or working and to achieve effective operation and efficient heat transfer throughout a wide range of body movements.
Another object of the invention is to provide a garment designed in such a way that the layer of fabric placed between the body and the heating packet acts as a partial insulating layer to prevent overheating or burning the skin yet at the same time allows heat to be transferred to the body in a comfortable manner.
It is still another object of the invention to provide a garment with heat-producing capability that it will also provide warmth to the user when the capacity of the heat-producing packet is used up or during periods that are not sufficiently cold as to require the use of a heat-producing packet.
These and other more detailed and specific objects of the present invention will be apparent in view of the following description setting forth by way of example but a few of the various forms of the invention that will be apparent to those skilled in the art once the principles described herein are understood.